NEW JOHNSONVILLE, Tenn. — The message began like so many others he receives these days.

“Hey, you don’t know me, but …”

Morgan Daniel doesn’t shrug off messages like that. He can’t, lest he ironically find his name on the naughty list.

He kept reading.

A woman explained her 9-year-old son Karson’s story. He was sick at St. Jude Hospital in Memphis, a children’s hospital where kids with catastrophic diseases can be treated free of charge. Her son had stomach cancer and happened to be a big Tennessee Vols fan. He’d seen the pictures, but never met him in person. He was hoping for a visit.

His mom reached out to Santa Vol.

“Is there any way you can come by and visit?” she asked.

Santa Vol scheduled a visit, fed his reindeer and settled into his sleigh (or maybe it was his white 2004 Nissan Frontier truck), and made the 150-mile trek to St. Jude on the banks of the Mississippi River, spending his...